6539991533 has 4 divisors (see below), whose sum is σ = 6553645440. Its totient is φ = 6526337628.

The previous prime is 6539991527. The next prime is 6539991541. The reversal of 6539991533 is 3351999356.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6539991533 - 2²⁴ = 6523214317 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6539991583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6826235 + ... + 6827192.

It is an arithmetic number, because the mean of its divisors is an integer number (1638411360).

Almost surely, 2^6539991533 is an apocalyptic number.

It is an amenable number.

6539991533 is a deficient number, since it is larger than the sum of its proper divisors (13653907).

6539991533 is a wasteful number, since it uses less digits than its factorization.

6539991533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13653906.

The product of its digits is 2952450, while the sum is 53.

The square root of 6539991533 is about 80870.2141273287. The cubic root of 6539991533 is about 1870.0751619346.

The spelling of 6539991533 in words is "six billion, five hundred thirty-nine million, nine hundred ninety-one thousand, five hundred thirty-three".